.drawer {
    position: absolute;
    top: 0;
    right: -310px;
    bottom: 0;
    z-index: 99;
    padding: 10px;
    width: 300px;
    box-sizing: border-box;
    background-color: #fff;
    box-shadow: 2px 1px 10px 2px #7a7a7a;
    transition: all .2s;
}
.expand {
    right: 0;
}